Method for extending bar code pdf 417 coding capacities

ABSTRACT

A process to extend the data encoding capacity using the PDF 417 bar code comprising a first step of compressing the data, the data being read by data acquisition hardware linked to scanning hardware connected to an information system, wherein the data is distributed using specific algorithms into a series of symbols that are dynamically linked to carry out a second compression, an element is introduced to control the integrity of the information and the formatting and reading of the data is controlled directly by the information system.

BACKGROUND OF THE INVENTION

[0001] The technical scope of the present invention is that of automaticidentification processes using bar codes, such as for example the codeknown under the name PDF (Portable Data File) 417.

[0002] In 1996, this PDF bar code generated a lot of interest in theUnited States of America with the supply of the corresponding scanners.

[0003] This bar code is known to provide a substantial encodingcapacity, which is not the case for known, widely distributed, barcodes. This encoding capacity is such that this bar code is no longerquantitatively different but qualitatively different from otheridentification tools. Its identification role does not consist in merelycalling for data, but in providing data directly, at a very competitivelevel of reliability and system possession cost with respect to thatimplemented in different technologies such as chip cards, PCMCIA cards,or radio labels.

[0004] However, in the gap in needs that bi-dimensional symbologies havecreated, the limit of 1,000 octets offered by the PDF 417 bar codesremains unsurpassed by other previously mentioned supports. For moredetails, reference may be made to the document published by AssociationIdentification Manufacturers in UNIFORM SYMBOLOGY SPECIFICATION PDF 417.

[0005] We already know how to distribute and retrieve information onseveral PDF 417 bar codes. But reading must be carried out in the exactorder in which the information was encoded to obtain a coherent message.Moreover, when the information is of the binary type, a loss has beennoted leading to a recognition by the control bar code that causesdisturbances. Lastly, there is no way to control the integrity of theinformation.

SUMMARY OF THE INVENTION

[0006] This is why the subject of the invention aims to create a newassembly based on PDF 417 bar codes whose encoding capacity no longerpresents any mathematical limits but only physical ones, and whichallows the use of commercially-available scanners not requiring anymodifications.

[0007] The invention thus relates to a process to extend the dataencoding capacity using the PDF 417 bar code after a first classicalstep of compressing the data, the data being read by data acquisitionhardware linked to scanning hardware connected to a information system,wherein the data is distributed using algorithms into a series of barcodes that are dynamically linked to carry out a second compression, anelement is introduced to control the integrity of the information andthe formatting and reading of the data is controlled directly by theinformation system.

[0008] According to one characteristic of the invention, the data isdistributed in packets of 1 KO, whatever its volume.

[0009] According to another characteristic, the data acquisition and theapplication on reception systems are integrated into the informationsystem to which the reading hardware is connected.

[0010] One essential advantage of the invention lies in the fact thatthe volume of data read is not subject to specific reading hardware andto the size of its memory.

[0011] Another advantage lies in the absence of constraints linked tothe reading order of the PDF bar codes.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Other characteristics, details and advantages of the inventionwill be more apparent after reading the additional descriptions givenhereafter by way of illustration and in relation to a drawing on whichthe single FIG. 1 represents an organisation diagram.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0013] As indicated previously, we are freed from the current limitsimposed by commercially-available scanners whilst ensuring as manytransmissions as readings, by reconstituting the data by the randomaccess memory of the computer and implementing thecompression/decompression algorithms using fractals and data encryptionalgorithms.

[0014] It is thus possible for a standard commercially-available scannerto be used that is not saturated by the quantity of data to betransmitted to a computer integrated into the data acquisition hardware,then to the information system. An additional threshold is thus reached,the increase in the encoding and decoding capacity.

[0015] To go beyond the limits of the scanner, an unlimited quantity ofdata is codified and distributed in a series of dynamically linkedsymbols. Each symbol thus represents a given quantity of the overallcodification. The dynamic link allows manipulation errors, for exampleinverting the reading order, accidental double reading or non validationin the event of the omission of a symbol, to be avoided. All the datamay, for example, be distributed in a set of four symbols. These foursymbols are then read and the information is recomposed by theinformation system. With this new method it is understood that it is nolonger the data acquisition hardware, nor the scanner, for example, thatinterprets the data, but the information system itself, which amounts tocarrying out the interpretation by a power of computation that hasnothing in common with the intrinsic capacity of the scanner. The roleof this computing power is thus to recreate the structure of theinformation from each packet that carries the description of the linkswith the full set of packets. As a result, the process according to theinvention allow this use of commercially-available peripherals requiringno particular modification. The process according to the inventionallows us to overcome the physical and mathematical limits of the PDF417 bar code described according to current standards, thereby allowingsubstantial volumes of information to be processed whilst remainingcompatible with commercially-available printing and reading means. Theinvention thus affords a considerable advantage. Moreover, the bar codesmay be read in any order and certain bar codes may be read twice withoutany disturbance to the system and without losing the integrity of theinformation.

[0016] By way of example, a volume of information of around 800 KO maybe integrated into four PDF 417 bar codes.

[0017] Thus, a first data compression is carried out in a classicalmanner, then the compressed information is reordered into packets ofinformation using polynomial functions in order to achieve a secondcompression and an integrity parity control command is introduced. Indecompression mode, the integration is firstly read using theinformation system, a micro-computer for example, then the informationis interpreted and the initially compressed information is retrieved.The integration mode is thus recognised in the interpretation anddecompression tool.

[0018] A large quantity of data is thus retrieve for the final user in atransparent and secure manner.

[0019]FIG. 1 shows the organisation of a system using the processaccording to the invention. The information system 1 is a dedicatedprogramme that encodes and decodes the data and is connected to dataacquisition hardware 2, for example a micro-computer, incorporating acomputer 3. The hardware 3 is connected to a printer 4 that prints oneor several PDF 417 bar codes 5 resulting from the encoding of theoriginal data. Inversely, the PDF 417 bar code may be read by a scanner6 that is connected to the data acquisition hardware 2 whose data isdecoded by the information system 1 so as to restore the informationcontained in the PDF 417 bar code into a readable form. If the codes aremultiple, no reading order, as previously indicated, is imposed and thesystem does not deliver any information until all the codes have beenread at least once.

What is claimed is:
 1. A process to extend the data encoding capacityusing the PDF 417 bar code comprising a first step of compressing thedata, the data being read by data acquisition hardware linked toscanning hardware connected to an information system, wherein the datais distributed using specific algorithms into a series of symbols thatare dynamically linked to carry out a second compression, an element isintroduced to control the integrity of the information and theformatting and reading of the data is controlled directly by theinformation system.
 2. A data extension process according to claim 1,wherein the compressed data is distributed in packets of 1 KO, whatevertheir original volume.
 3. A data extension process according to claim 1,wherein the data acquisition system and the application on reception ofthe data are integrated into the information system to which the readinghardware is connected.
 4. A data extension process according to claim 2,wherein the data acquisition system and the application on reception ofthe data are integrated into the information system to which the readinghardware is connected.